This application claims the priority of Japanese Patent Applications No. 2001-1828 filed on Jan. 9, 2001 which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to an electronic endoscope apparatus, specifically to a configuration of an electronic endoscope apparatus wherein electronic endoscopes having an imaging device with different pixel densities are connected to a common processor unit.
2. Description of the Prior Art
FIG. 3 shows the configuration of a part of a conventional electronic endoscope apparatus and, as shown in the figure, a CCD (Charge Coupled Device) 2, which is a solid-state imaging device, is disposed at the tip of an electronic endoscope 1. The endoscope 1 is configured to connect detachably to a processor unit 3, and the processor unit 3 is provided with a drive pulse generation unit 4 for generating drive pulses to drive the CCD 2 and a signal processing circuit 5 for performing various signal processing to form image signals (video signals) based on the output signal of the CCD 2. And the output of the signal processing circuit 5 is supplied to a monitor 6.
According to the configuration described above, although not shown in the figure, light is emitted from the tip part, and the object to be observed is imaged with the CCD 2 under the emitted light and, at the CCD 2, electric charges accumulated in each pixel are read out as the image information by the drive pulse generation circuit 4. Thus the drive pulse generation circuit 4 generates various drive pulses such as a horizontal drive pulse, a vertical drive pulse, and a sweep-out (SUB) pulse, and these drive pulses are provided to the CCD 2 and thereby the image information constituting the video signal is read out.
The output signal of the foregoing CCD 2 is supplied to the signal processing circuit 5, where various image processing such as correlated double sampling, amplification, and gamma correction are performed and, from the signal processing circuit 5, video signals such as R (Red), G (Green), B (Blue) signals or Y (Luminance)/C (Color) signals are outputted to the monitor 6. Consequently, an observation image of the object to be observed is displayed in color.